EP0450939A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Improvements in hydroxyapatite coatings of substrates
Assignee: Norian Corp
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Filing: 1991-04-03
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Granted: —
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Expires: 2011-04-03
Abstract
Abstract Methods, compositions and apparatus are provided for coating a substrate with a strongly adherent hydroxyapatite coating, which allows for ingrowth of natural bone and strong bonding between the coating and the substrate. The procedure provides for coating under conditions which form sticky particles which bind to the substrate to from a crystalline hydroxyapatite coating. The coating has particular application for prostheses, where porous areas of the prostheses are completely coated with a thin sturdy coating of hydroxyapatite. The apparatus comprises a coating trough in which the substrates are present and the reactive components added. The medium is recirculated in an outer circuit through a distribution tank solution preparation tank and coating trough. Means are provided for maintaining temperature and pH. The substrates are maintained in a line normal to the flow in the trough and can be rotated to ensure even coating.
Inventors
- 👤 Brent R. Constantz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 16:56
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/28; A61L27/30; A61L27/32; A61F; A61F2310/00; A61F2310/00389; A61F2310/00592; A61F2310/00796; Y; Y10; Y10S; Y10S623/00; Y10S623/901
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
104 words
A method for preparing a uniform, strongly adhering, high surface area hydroxyapatite coating to a substrate, said method comprising: contacting a solid substrate with a streaming solution at an elevated temperature into which is introduced a source of soluble calcium ion and a source of soluble phosphate ion at a concentration which provides colloidal particles of hydroxyapatite which stick to said substrate to form a coating providing for continuous accretion of hydroxyapatite to coat said substrate; wherein upstream of said substrate are said source of calcium ion which is proximal to said substrate and said source of phosphate which is distal to said substrate.
Claim 2
Dependent Claim
33 words
A method according to Claim 1, wherein a source of base is provided to maintain the pH in the range of 6.8 - 8, said source of base being downstream from said substrate.
Claim 3
Dependent Claim
24 words
A method according to Claim 1 or Claim 2, wherein said calcium ion and phosphate ion sources are at concentrations substantially stoichiometric for hydroxyapatite.
Claim 4
Dependent Claim
36 words
A method according to Claim 1, Claim 2 or Claim 3 wherein at least one additional ion selected from the group consisting of carbonate, fluoride, bicarbonate, hydrogen, or dibasic phosphate is present in said hydroxyapatite coating.
Claim 5
Independent Claim
184 words
A method for preparing a hydroxyapatite coating strongly adhering to a substrate, said method comprising: contacting a solid substrate with a solution stream comprising a source of soluble calcium ion and a source of soluble phosphate ion at a temperature in the range of 60-90 degrees, a pH in the range of about 5-8.5 and at a first concentration providing for small crystal formation forming a first coating on said solid substrate, wherein said calcium ion source is introduced into said stream proximal to said solid substrate and said phosphate ion source is introduced into said stream distal to said solid substrate; repeating said contacting of said solid substrate with said small crystal coating at lease once with a solution comprising a source of soluble calcium ion and a source of soluble phosphate ion at a temperature in the range of 60-90 degrees, a pH in the range of about 5-8.5 and at a second concentration at least two-fold lower than said first concentration providing for larger crystal formation forming a coating over said first coating; and removing said solid substrate from said solution.
Claim 6
Dependent Claim
12 words
An hydroxyapatite coated substrate prepared according to Claim 1 or Claim 5.
Claim 7
Dependent Claim
11 words
A substrate according to Claim 6, wherein said substrate is porous.
Claim 8
Dependent Claim
19 words
A substrate according to Claim 6 or Claim 7, wherein said substrate is comprised of metal or hardened plastic.
Claim 9
Dependent Claim
19 words
A substrate according to Claim 8, wherein said substrate is a prosthesis device comprised of Co-Cr or Ti alloy.
Claim 10
Dependent Claim
28 words
An hydroxyapatite coated substrate prepared according to any one of claims 6 to 9 comprising a bone growth activating amount of a growth factor for osteoblasts or collagen.
Claim 11
Dependent Claim
15 words
A substrate according to Claim 10, wherein said coated substrate comprises a bone growth factor.
Claim 12
Dependent Claim
12 words
A substrate according to Claim 10, wherein said coated substrate comprises collagen.
Claim 13
Independent Claim
120 words
An apparatus for preparing a strong adhering hydroxyapatite coating to a substrate, said apparatus comprising; a coating trough; a distribution tank; a solution preparation tank; means for circulating a coating medium in a continuous manner in a circuit from said coating trough to said distribution tank to said coating trough; heating and pH control means for controlling the temperature and pH of said circulating medium; source means for adding phosphate, neutralizing base, and calcium, where the calcium source means is in proximity to said substrate as compared to the said phosphate and neutralizing base source means neutralizing base source is downstream and from said substrate; and changing the position of said substrates to the direction of flow in said trough.
Claim 14
Dependent Claim
18 words
An apparatus according to Claim 13, further comprising means for filtering particulate matter upstream from said distribution tank.
Claim 15
Dependent Claim
17 words
An apparatus according to Claim 13 or Claim 14, wherein said changing means is a rocking means.
References Cited (Backward Citations)
No citation records indexed.
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